X-linked recessive diseases
Duchenne muscular dystrophy males 1/3,500
- early onset, progressive muscle weakness, severe skeletal muscle degeneration
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Haemophilia A males 1/5,000
- deficiency of clotting factor VIII, excessive bleeding from minor traumas, internal bleeding
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Fragile X syndrome males 1/1,500, females 1/2,500
- mental retardation
- mildly affects 1/3 of female carriers- appears partially dominant